1. Field of the Invention
The present invention relates to an image capturing apparatus, a method of detecting tracking object, and a computer program product.
2. Description of the Related Art
In image capturing apparatuses typified by video cameras and digital cameras, an image capturing apparatus having an object tracking function has been widespread. The object tracking function is a function to move a focus area and such in an image capturing range of the image capturing apparatus in response to the movement of a tacking target of a photographic subject to allow focus adjustment, calculation of an exposure condition, and the like to be carried out by following the moving photographic subject.
In image capturing apparatuses having this type of object tracking function, several methods of selecting a tracking target object are known including a method to set an object that is selected from an image displayed as a monitor image by the operation of a user as a tracking target, a method to set a face of a human that is detected by a face detection process for an image as a tracking target, and a method to set an object detected by an auto-focus (AF) operation as a tracking target.
For example, Japanese Patent Application Laid-open No. 2009-177503 discloses an image capturing apparatus that sets an object selected by the operation of a user as a tracking target. More specifically, in the image capturing apparatus disclosed in Japanese Patent Application Laid-open No. 2009-177503, a rectangular frame is superimposed on a view image displayed on a monitor as a moving image. When the user presses a decision button while an object is positioned inside the frame displayed in the view image, the image capturing apparatus sets the object displayed inside the frame as a tracking target object and starts the operation of object tracking.
However, in the conventional methods, the fact that the tracking target object is selected by the operation of the user, the face detection process, the AF operation, and the like makes it difficult to set the object as a tracking target unless the tracking target object is held still when selecting the object. In other words, it is difficult to select as a tracking target an object that is moving when starting up the image capturing apparatus, making it impossible to start the tracking operation with a moving object as the tracking target.